ANIMAL INTELLIGENCE. 35 



R was still another pen similarly constructed, with four 

 possible avenues to be taken. (See Fig. 15.) 



Fig. 13. Fig. 14. Fig. 15. 



S was a pen with walls 11 inches high. On the right side 

 an inclined plane of wire screening led from the floor of the pen 

 to the top of its front wall. Thence the chick could jump down 

 to where its fellows and the food and drink were. S was 

 17 X 14 in size. 



T was a pen of the same size as S, with a block of wood 3 

 inches by 3 and 2 inches high in the right back corner. From 

 this an inclined plane led to the top of the front wall (on the 

 right side of the box) . But a partition was placed along the 

 left edge of this plane, so that a chick could reach it only via 

 the wooden block, not by a direct jump. 



U was a pen 16 x 14 x lO inches. Along the back to- 

 ward the right corner were placed a series of steps i ^ inches 

 wide, the first i, the second 2, and the third 3 inches high. In 

 the corner' was a platform 4x4, and 4 high, from which access 

 to the top of the front wall of the pen could be gained by 

 scrambling up inside a stovepipe 11 inches long, incHned 

 upward at an angle of about 30^. From the edge of the wall 

 the chick could of course jump down to food and society. The 

 top of the pen was covered so that the chick could not from the 

 platform jump onto the edge of the stovepipe or the top of the 

 pen wall. The only means of exit was to go up the steps to 

 the platform, up through the stovepipe to the front wall, and 

 then jump down. 



The time-curves for chicks 90, 91, 92, 93, 94 and 95, all 

 2-8 days old when experimented on, follow on page 37. The 

 scale is the same as that in the curves of the cats and dogs. 



